Regulating device for heavy oil engines



Jan. 24, 192s. 1,657,394

G. HELD REGULATING DEVICE FOR HEAVY OIL ENGINES Filed NOV. 22, 1927 e@ LQZM @QW a desired angle by the adjustment screw 15 tional Patented Jan. 24, 1928.

UNITED STATES GEORGES HELD, OF BRUSSELS, BELGIUM.

BEGU'IICJAQIIIIG'y DEVICE FOR HEAVY OIL ENGINES.

Application led November 22, 1927, Serial No. 234,992, and in France October 1, 1926.

My present invention relates to engines of the two stroke type, which are provided with a pump for the liquid fuel supply, such for instance as the engines specified in my Patent No. 1,613,226 granted January '4, 1927 and has for its object the improvement of the regulation of the engines of this type.

Various structural features of my invention are shown in the accompanying. drawin s, in which:

ig. 1 is a vertical sectional view of the regulating device according to my invention, and Fig, `2 is a corresponding plan View, vpartly in section. Fig. 3 is a vertical sec`- view taken along the broken line 3-3 of Fig. 2. Fig. 4 is a detail view of one of the eccentrics. Fig. 5 is a sectionalview taken along line 5 5 of Fig. 1.

They engine represented by way of example is of the two-cylinder type, but my regulating arrangements are obviously applicable to any number of cylinders. The said engine is of the two-stroke type.

The fu'el pump is not shown in detail, as 'it is of the type known per se.

Referring to the figures, the apparatus is constructed as follows:

r.The end ofthe pump piston or plunger is shown at I (Fig. l) it is actuated by a .lever 2 whose position and stroke are regulated b the cams 3 which are movable along the va ve control shaft of the engine 3'; said cams have a variable section in the direction of their length, and two such cams are provided. The said cams coactA with the rollers 2 mounted on the two respective levers 2. The said levers can be regulated with reference to the pump by means of an eccentric 13 (Figs. 1 and 5) mounted on the rotating axle, which can be moved through (Fig. 3), at whose end is mounted the grooved roller 15 whereof the groove coacts with a tooth 14 of suitable shape disposed upon said eccentric. The cams 3 are move on their shaft by two respective forked levers 4-4 whose ends make contact with the flanges at the ends of the cams; said levers are pivoted at A1 and are secured to the toothed sectors 5-5 having special teeth, as will be further specified, and engaging a pinion 6 keyed to the vertical shaft 6 secured to a piston 7 which is movable in a cylindrical part of the pressure chamber 8,

said chamber being connected by means of the pipe 16 with the scavenging pump or the oil pump. A spring 11 is mounted below the piston 7 and holds it in its upper position when no pressureis exercised upon the piston.

The teeth of the sectors 5 5 have a suitable height and are given a spiral shape, like the' corresponding pinion, so that any lengthwise movement of the pinion 6 will cause rotation of the sectors. The rotation of the vertical shaft 6 will also cause rotation of the said sectors.

This rotation is effected by means of an arm 9 (provided with a ball joint member) keyed to the shaft 9 actingupon a socket in which is slidable the shaft of the spiral' pinion 6; said arm 9 is connected by the said ball joint member with the rod-and-link gear of the accelerator which is controlled by V the usual pedal or by a handle mounted on the steering wheel. The pinion may have two different movements, i. e. a rotation due to the arm 9 or a vertical motion due to the displacement of the piston 7.

The members `9 and 6 are coupled together by means of a wedge 10 (Fig. 1), which is inserted into slots within the rod of the piston 7.

One end of the lever 2 actuating the pump surrounds the eccentric 13 (Figs. l and 5) whereof the eccentricity is horizontally disposed when-in the middle position; the said eccentric surrounds the eccentric 12, whose eccentricity 1s vertically disposed when in.

the middle position.

The eccentric 12 is the same for the devices respectively actuating the pumps of the engine cylinders, one eccentric being used for each pump' (sec Fig. 3). This eccentric 12 is pivoted into brackets 17-17, attached to a support 18, the base of which is bored at 19-19 to receive the pivots 4: of the forked levers L1. Each lever 2 is provided with `a d sleeve 2O inside which is lodged the corresponding eccentric 13. All the eccentrics carry a tooth 14: (Fig. 4) for the purpose above specified.

The operation of my regulating device is as follows: The tooth 14 of the eccentric 12 is turned in order to move the roller 2 of the lever' 2 in the horizontal direction. By this movement I am venabled to determine with accuracy the screws 15 c oacting with the instant at which the fuel will be supplied to the engine cylinder. This adjustment may be made during tests upon the engine, correcting at the same time any defective mounting of the cam 3; the screw 15 coacting with the tooth 14 of the eccentric 13 may be turned in order to adjust the play between the lever 2 and the end of the piston of the fuel pump 1. This preliminary adjustment may be made while the engine is running. When the instant of the fuel supply-is detinitely determined and the strokes of all the pump pistons are made equal, the screws 15 are secured by set-screws and are not to be further interfered with. When the motor" vehicle is traveling, the arm 9 is actuated by the accelerator pedal or by a handle on the steering wheel, and such motion will displace the cams 3 along the valve -control shaft. An increase of ressure on the pedal will lengthen the stro e of the pump piston, thus increasing the power of the engine, or the inverse action may take place. The tension of the spring 11 is chosen in suoli manner that it will be less than the scavenging pressure, so that the piston 7 will always be in the lower position when the vehicle is rupning.

The no-load operating of a heavy oil engine offers peculiar diiliculties due to the fact that the pum supplies a minimum quantity for each wor ring stroke of the piston; this quantity does not depend upon the number of revolutions per minute, but depends solely upon the position of the arm which remains stationary when the accelerator pedal is released. 'Since the running is not e uilibrated, the speed will vary between rat er wide limits. When the engine is running with no load, the. requisite normal equilibrium is obtained by means of the piston 7. As is well known, the scavenging pressure in the two-stroke engine increases rapidly with the number of revolutions per minute, and is abou; proportional to the square of the s ee pThe tension of the spring l1 which .tends to raise the piston corresponds to the scavenging pressure at no load, and the piston is thus near its middle position when running idle. Should the engine speed increase from accidental causes, the scavenging pressure will at once increase; the piston descends to a slight degree, and the pinion 6 will slightly pivot the lever Li--due to the spiral shape of the teeth-so that the cam 3 will be moved to the side corresponding to the reduction of the stroke of the fuel pump, and the engine speed will thus be reduced. On no load, the engine speed will `depend solely upon the tension given to the spring 11, and may thus be determined at will.

When the accelerator pedal is pressed down, the engine speed will at once increase, and since the scavenging pressure also increases, the piston 7 will be driven to the end of its stroke. During the travel of the vehicle, the piston will remain stationary.

The said regulating method thus provides for the automatic regulating of the no-load running as well as the normal regulating of the speed by the use of the accelerator.

Instead of using the pressure of the scavenging air, I may employ the pressure of the oil in an engine in which an oil pump is utilized for central lubrication. This pressure also increases when the engine speed increases. l

Claims:

l. In a heavy oil vengine of the two stroke type having a fuel pump, a rotatably adjustable device for regulating the stroke of the fuel pump, means for adjusting said device to control the stroke of the fuel pump during 11o-load operation,l and additional means for adjusting said device at the will of the operator.

2. In the combination set forth in claim 1, said no load operation adjusting means comprising pneumatic means responsivf` bo change of speed of the engine.

3. In the combination set forth in claim 1, said no-load operation adjusting means comprising pneumatic means responsive to .change in pressure of the scavenging air.

4. In a heavy oil engine of the two-stroke type having a fuel piston punip and an accelerating. means, a device for regulating the stroke of the fuel pump, a cylinder, a piston lengthwise movable and also rotatable within the cylinder, a spring below the piston inside the cylinder, a source of fluid pressure which varies with the speed of the engine, a pipe admitting said fiuid pressure to the cylinder above the piston, a piston rod, spiral shaped gear means operatively connecting the piston rod and the regulating device to adjust said regulating device `both by its lengthwise movement and rotation of said piston rod, and means controlled by the accelerating means for rotating the piston rod.

5. In a heavy oil engine of the two-stroke type having a fuel piston pump and an accelerating device, a cam device for regulating the stroke of the fuel pump, rotating levers for controlling the cam device, a cylinder, apiston lengthwise movable and rotatable within the cylinder, a spring below the' piston inside the cylinder, a source of fluid pressure which varies with the speed of the engine, a pipe admitting said Huid pressure the cylinder above the piston, a piston rod, a pinion with spiral shaped teeth keyed to the under end of the iston rod, sectors with spiral-shaped teet meshing with the pinion and secured to the rotating levers controlling the cam-device, and means controlled by the accelerating device for rotating the upper end of the piston rod.

6. In a heavy oil engine of the twostroke type havin a, fuel piston pump, a shaft, cams movab e alon the shaft, levers controlling the stroke o the fuel pump, rollers provided at one end of said levers and coacting with the cams, sleeves provided at the other end of the levers, a rotatable axle inside the sleeves, an eccentric keyed In testimony whereof I affix m signature.

GEORGE HELD. 

